Abstract

Pyruvate dehydrogenase complex (PDC) is a highly organized multienzyme complex that plays a key role in glucose metabolism
providing a direct link between glycolysis and the tricarboxylic acid cycle. PDC is tightly regulated according to changing
demands in glucose consumption in different tissues and under different nutritional and pathophysiological conditions.

Activity of PDC and its regulation in higher eukaryotes by phosphorylation/dephosphorylation catalysed by isoenzymes of PDKs and PDPs, respectively.

Figure 2.

Sequence of reactions catalysed by PDC. The partial reactions (1 – 5) catalysed by three catalytic components are identified.

Figure 3.

Two models of the mammalian PDC organization. (a) Cut‐away model of a fully assembled PDC. E3 molecules (red) are bound inside the pentagonal dodecahedron core formed by 60 inner domains of E2 and 12 inner domains
of BP (green). E1 (yellow) is bound to the E2‐core through the inner linkers of E2 (blue) (Zhou et al., ). (b) A model of the inner core formed by E2 and BP. Twelve inner domains of BP (red) replace 12 inner domains of E2 and bind with 48 inner domains of E2 (blue) to form a 60‐mer pentagonal dodecahedron
(Hiromasa et al., ).

Effect of αH15 mutation on the E1 structure. (a) Structure of the α subunit of E1 in the region of αH15. (b) Simulated structure
of αH15R. Residue in position 15 is shown in yellow. Hydrogen bonds are displayed (Korotchkina et al., ).